浅低温联合七氟烷对大鼠海马脑片氧糖缺失损伤的影响

目的 探讨浅低温联合七氟烷对大鼠海马脑片氧糖缺失损伤的影响.方法 雄性SD大鼠,体重80～100 g,断头处死,剥离海马,制备脑片.取符合标准的海马脑片32片,随机分为4组(n=8):氧糖缺失组(OGD组)、七氟烷组(Sev组)、浅低温组(MH组)和浅低温+七氟烷组(MH+Sev组).OGD组和MH组分别于37℃或32℃下用经95%N2-5%CO2混合气体饱和的无糖(氧糖缺失)人工脑脊液(ACSF)灌流脑片14 min;Sev组和MH+Sev组分别于37℃或32℃下用预先经4%七氟烷平衡的有氧有糖ACSF灌流脑片14 min,再用预先经4%七氟烷平衡的氧糖缺失ACSF灌流脑片14 min.记录海马CA1区缺氧到复氧1 h期间的顺向群峰电位(OPS).采用比色法测定乳酸脱氢酶(LDH)释放率.结果 与OGD组比较,Sev组和MH组OPS消失时间延长,OPS恢复程度升高,MH组LDH释放率降低(P<0.05或0.01);与MH组比较,MH+Sev组OPS消失时间延长,OPS恢复程度和恢复率升高,LDH释放率降低(P<0.05或0.01);与Sev组比较,MH+sev组OPS消失时间延长,OPS恢复程度和恢复率升高,LDH释放率降低(P<0.05或0.01).结论 浅低温(32℃)联合4%七氟烷可减轻大鼠海马脑片氧糖缺失损伤.

Effects of combination of mild hypothermia and sevoflurane on oxygen-glucose deprivation injury in rat hippocampal slices

Objective To investigate the effects of mild hypothermia combined with sevoflurane on oxygen-glucose deprivation injury in rat hippocampal slices. Methods Male SD rats weighing 80-100 g were anesthetized with ether and decapitated. The hippocampus were removed and sagittally sliced (400 μm thick) and placed in artificial cerebrespinal fluid (ACSF) aerated with 95% O2-5% CO2. Thirty-two hippocampal slices were randomly divided into 4 groups (n=8 each): group Ⅰ OGD;group Ⅱ sevoflurane (Sev);group Ⅲ mild hypothermia(MH) and group Ⅳ MH + Sev. In group Ⅰ and Ⅲ , the hippocampal slices were perfused with glucose-free ACSF and aerated with 95%N2-5%CO2 for 14 min at 37℃ and 32℃ respectively. In group Ⅱ and Ⅳ, the hippocampal slices were perfused with oxygenated, glucose-containing ACSF saturated with 4% sevoflurane for 14 min, then perfused with oxygen/glucose-deficient ACSF saturated with 4% sevoflurane at 37℃ and 32℃ respectively. Electrophysiological technique was used to record the amplitude of orthodromic population spike (OPS) in the stratum pyramidale of CA1 region during OGD and 1h rcoxygenation.The release rate of LDH was determined using chromatometry. Results Compared with group Ⅰ , the disappearance time of OPS was significantly prolonged, the recovery amplitude of OPS was significantly increased in group Ⅱ and Ⅲ and the release rate of LDH was significantly decreased in group Ⅲ (P<0.05 or 0.01). Compared with group Ⅲ , the disappearance time of OPS was significantly prolonged, the recovery amplitude and rate of OPS were significantly increased and the release rate of LDH was significantly decreased in group Ⅳ (P<0.05 or 0.01). Compared with group Ⅱ, the disappearance time of OPS was significantly prolonged, the recovery amplitude and rate of OPS were significantly increased and the release rate of LDH was significantly decreased in group Ⅳ (P<0.05 or 0.01). Conclusion Combination of mild hypothermia(32℃) and 4% sevoflurane can attenuate OGD injury in rat hippecampal slices.